Stay-bolt.



No. 823,825., PATENTEDIJUNE 19, 1906. G. s. THOMPSON.

STAY. BOLT.

APPLICATION FILED 00TH], 1905- Z22, wwmws, 1 v Xmwmw. MM- W G. S. THOMPSON. STAY BOLT.

APIPLIOATION FILED 0017, 1905.

2 SHEETS-SHEET 2.

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canto suits PATENT .S TAfY- Spec fica ion o Lette s retent- Patented .J-une 1.9.

' To atl whom it may concern;

nection with a two-part stay-bolt.

Be it known that i[, :GEORGE S. THOMPSON, a citizen of the United States, residing at Hockessin, Newcastle county, and State of Delaware, have invented certain new and useful Improvements in Stay-Bolts, of which the following is a specification.

My invention relates to the form and constructionof articulated stay-bolts, especially those of the character disclosed in Letters Patent No. 792,863, issued to me June 20, 19.05, the present invention being designed to embody in a three-part stay-bolt the principles and advantages therein set forth incon- As in the latter case, while my articulated bolt is applicable for various other uses, it is intended particularly for use in steam-generators, es.- pecia-lly locomotives, between the outer shell and the fiIGubOX shell.

The main object is to attain a three p a-rt articulated stay-bolt which while capable .of lateral flexure by reason of its joints shall at thesame time be tactically unyielding axially .or longitudinally, so as to hold the boiler and fire-box firmly and rigidly in position with relation to each other, all looseness or play lengthwise of the 'b olt beingobv-iated by the peculiar construction .of the joints between the parts, as hereinafter more fully described.

As in my patent hereinbefore referred to,

.I attain a maximum of strength fora given size and thickness of bolt and prolong its life and usefulness by relieving the Weaker parts of all excessive pressure and distributing and neutralizing the strain, both of tension and compressionon the parts generally,'both.;dur-

ing manufacture, application, and use. I

alsov herein aim to preserve the flexibility of the stay-dealt as :a whole by preventing the accumulation or lodgment of sediment between the articulated-partszor joints, thusobviating lateral strain that might otherwise result from impaired flexibility.

Another feature .of my present invention is designed to afford prompt evidence .of any breaker fracture from anyicause occurringat theweaker art. of thestay-bolt, which is adjacent to. its connection with the fire-box plate, not because this bolt is weakened in any particular, but because the otheror outer end of the bolt, which was formerly the weaker end, has been materially strengthened.

A distinguishing feature of my present .in-Q

ventionlconsists the use .of a central Q9111):- lingi'link made in one piece without joint or .weld, which I accomplish by. forming the loops of both the eyebolt and the eye-head of straps which are passed through the and then bent over and welded to central fillers, the welded portions being then shaped and threaded for engagement with the boiler and fire-"box plates.

An advantage of my constnuctionof three: .art stay-bolt is that both eyebolt and eye.- head may be screwed'home simultaneously in the plates to which they are applied, the bolt v as a whole :being particularly rigid and as .of

one piece when supported and driven longir tudinall-y, since there is no looseness between the parts, the articulating bearingesurfaces being locked in intimate contact with .each other, also preventing the independent rota.- tion of either part upon the other. In this connection a feature of my inventionconsjists in forming the .eyebolt with a noseof lessdiameter than the threaded portion of the eye.- bolt tofacilitate the entrance and connection of the male screw-threadon the eyebo'ilt with the female screw-thread formed for its recep 'tion the fire-box plate.

The severest strainto which .thebolt is sub-- j-ected being that ofcom ression by reasonof the iunequalexp ansion .0 the plates to it is attached, since the fire-box plate visexposed to-a higher temperature .than-theboiler-shell, I so arrange and construct my parts that the force of compression is met .and expended upon the external surface of the couplinglink, the eyes .of which are protected by central depressions in the opposed concentric bearing purfacelof the eye-head and eyebolt, so that the ressure is transmitted to and through the ongitudinal sides of the link, as

hereinafter shown.

My invention also includes certain other features in the construction and arrangement of parts hereinafter described and claimed specifically.

In the accompanyingdrawings, Figure 1 is an elevation of my improved articulated-staybolt' applied to and between a boiler-shell and a furnacerplate. Fig. 2 is an elevation of the. bolt before application, the view be-i ing taken at right angles to Fig. 1. Fig. 3

is'asideelevation of the hller-usedin the for-i I I mation .of the eyehead Fig. 4, an edge view of the same at irightvangles to Fig. 3. 'Eigh 5' is a face .end view of the filler. Fig. .6 is a ;rear view .of the filler. 7 is a sction.

taken upon plane of line 7 7, Fig. 3. Fig. 8 is a side elevation of the coupling-link; Fig. 9, an edge view of the coupling-link. Fig. 10 is a central longitudinal section upon plane of line 10 10, Fig. 2; Fig. 11, a similar section of the Whole bolt, taken upon plane of line 11 11, Fig. 10. Fig. 12 is a detail view illustrating the construction of the eyebolt. Fig. 13 is a similar view illustrating the construction of the eye-head. Fig. 14 is a transverse section taken upon plane of line 14 14:, Fig. 13. Fig; 15 is a section taken upon the same plane after the sides of the strap have been compressed.

My improved articulated stay-bolt consists of a central coupling-link C, an eye-head H, and an eyebolt B. The coupling-link is formed preferably of a single piece of metal either cast or drop-forged without weld or joint. I thus attain a couplingof uniform texture and strength, which latter is further enhanced by forming the link with a broad central web 0, from which the body of the link tapers in either direction to merge into the knuckles c c, which are circular in crosssection, as will be seen more particularly by reference to Fig. 11. The eyes a c are formed With concave seats 0 c of the same radius as that of the knuckles 7L2 on the eyehead H and the knuckles I) on the eyebolt B,

- both of which knuckles are circular in crosssection, as will be seen by reference to Fig. 10. Back of the seats 0 c the eyes are enlarged to form eccentric spaces 0 c for the purpose not only of facilitating the insertion of the cylindrical strap-rods for the eyebolt B and eye-head H during the manufacture of the bolt, but also for a more important purposethat of avoiding contact between the internal surfaces of the eyes and the external convex surfaces of the loops of the eyebolt and stay-bolt, as will be seen by reference to Figs. 1, 10, and 11 of the drawings, and also for the purpose of avoiding the lodgment of sediment, as hereinafter set forth.

The eyebolt is constructed in substantially the same manner as set forth in my Letters Patent hereinbefore referred to, the only difference being that in the present case the eyebolt B is formed with an extension or nose 6 beyond the threaded portion 1) of the shank and is also formed with an internal recess or bore b extending from the end of the nose 1) preferably through and beyond the said threaded portion 5 of the eyebolt, as will be seen by reference to Figs. 10 and 11that is to say, in the formation of the eyebolt B a cylindrical rod 6 is passed through one of the eyes 0 of the coupling-link C and bent over to form the loop of the eyebolt, a central filler 5 being then inserted between the ends of the rod, which ends are then flattened and welded to the filler, after which the welded portions of the eyebolt are shaped and threaded, as shown, by well-known means.

As heretofore, the inner end of the filler b is formed with concave bearing-surfaces b b, with a central depression 1) between them, the said concave bearingsurfaces I)" I) being concentric with the knuckles b, the inner convex surface of which fits in the opposed concave seat 0 in the coupling-link G, as clearly shown in Fig. 10, by reference to which. it will also be seen that the concave bearingsurfaces 1) b of the eyebolt engage with the opposed concentric convex surface 0 of the link-knuckle. Thus the articulation of the parts is provided for without looseness or longitudinal play, the knuckles fitting each other snugly and being held to their respective seats by the concave bearing-surfaces I) b, which, however, do not interfere with the pivotal or lateral flexure of the parts upon each other Within ample limits.

The nose I) of the eyebolt B is reduced in. diameter to less than that of the threaded. portion 6 of the eyebolt and is preferably tapered toward the end also to facilitate its introduction into the tapped hole in the firebox plate F, the nose thus acting as a guide and centralizer for the tlneaded portion b of the shank, so that the engagement between the male and female screw-threads is easily effected during the operation of applying the stay-bolt as a whole to and between the boiler-shell S and the fire-box plate F. When thus applied, the telltale-bore b opens into the fire-chamber and in case of the rupture of the threaded shank admits water or steam. from the space between the shell S and plate F to the fire-box, thereby directing attention to the defect. I thus protect the eyebolt, because it is necessarily the weaker part of the bolt, relatively speaking, not because it has been weakened, but because the other parts of the stay-bolt, the coupling-link C, and the eye-head H have been materially strengthened by my structure of stay-bolt, and also because the stay-bolt is necessarily subjected to the greatest degree of strain or compression at its junction with the fire-box plate owing to the high degree of temperature, and, hence to the extremes of expansion and contraction to which the plate is subjected. The eye-head H is likewise formed from a central filler h and a strap 7t, consisting of a cylin drical rod, the rod being bent to form the knuckle k and the filler It being inserted between the ends of the rod, which are then flattened and welded to the filler, the welded portions being then shaped externally. In order to afford the required thickness of metal to form the head It, the filler is made with lateral extensions in which are formed recesses 71, h for the reception of the ends of the strap h.

The finished head h is preferably in the form of'a conic frustum peripherally threaded for engagement with a hole tapped for its reception in the boiler-shell S, and the base of 'BIaaBaB this conic section is formed with an extension h, which is polygonal in cross-section or therwise so formed as to provide for the simultaneous rotation of theeye-head and link C and eyebolt B upon their common longitudinal axes, for which purpose various wellknown mechanical expedients may be resorted to if the polygonal extension h is not desired.

The inner end or face of the filler is formed with the concave bearing-su=rfaces h h with a central depression or space h between I them, said concave bearing-surfaces h 71 being concentric to the knuckle .h and bearing against the opposed convex concentric surface a of the coupling-link, as will be'seen by reference to Fig. 10. Thus, as in the case of the articulation of the eyebolt B, the parts are held in intimate engagement with each other and no longitudinal looseness or play is possible in either direction, the stay-bolt being maintained at a prescribed length when the parts are extended withtheir longitudinal axes in alinement, so that considered axially the stay-bolt is practically unyielding and rigid in the transmission of longitudinal strain or compression, while flexible trans-' versely to adapt the parts to lateral strain. In this connection the coupling-link C is of special importance, since it readily adapts itself to and compensates for any lack of perfect axial alinement from any cause between the eye-headH and the eyebolt B.

The recesses or depressions h and 6 in the inner facesof the eye-head H and eyebolt B, respectively, are of importance in that they relieve the central portions of the knuckles c c of the coupling-link from compression, transferring the pressure to the sides of the link, where it can do no possible harm.

The eccentric extensions 0 c of the eyes 0 c of the coupling-link 0 not :only obviate contact with the convex external surfaces .of the eye-head H and eyebolt B, thereby pr0tecting the knuckles of said parts against the force-of compression-during use, but they also perform another important function in that they protect the knuckles against injury during the upsetting of the metal in the manufacture of the bolt, and thereby preserve smooth even peripheral surfaces upon which sediment can find no resting-place, the collection of sediment between the joints having a tendency to impair the usefulness and strength of the stay-bolt.

By my construction of eye-head the outer end of the stay-bolt is rendered much more substantial and durable than heretofore, the settingof the fiber of the metallic strap by compression, so that resilience and stretch is eliminated, &c., asset forth in my said Letters Patent in connection with the description of the formation of my special form of eyebolt, being advantages inherent in the present structure-of both eye-head and eye- 'bolt, so that they do not need to be recapitulated herein.

N 0 claim is made in this application to the method of making the bolt herein described, as the same forms the subject-matter of m divisional application, Serial N o. 2 1 0,002, filed April 3, 1,906.

What I claim as my invention, and desire to secure by Letters Patent, is

1. An articulatedstaybolt having an eyehead consisting of a central filler the inner edge of which is formed with a concave bearing-surface concentric to the opposed inner surface of the eye-loop for engagement with the concentric surface of the part to which the eyebolt is coupled, and a strap formed of a cylindrical rod looped into the eye of the part to which the eye-head is coupled, said cylindrical rod being bent to form the eye of the head, and having its ends welded to the filler on opposite sides thereof, for the purpose described.

2. An articulated stay-bolt having an eyehead consisting of .a .central filler the inner edge of which is formed withconcave bearingsurfaces with a depression between them,

said concave bearing-surfaces being concentric to the opposed inner surface of the eye loop or knuckle for engagement with they cylindrical rod looped into the eye of the part to which the eye-head is coupled, said cylindrical rod being bent to form the eye of the head and having its ends Welded to the filler on opposite sides thereof, for the purpose described.

3. An articulated stay-bolt. having an eyehead consisting of a central filler the inner edgeof which is formed with a concave bearing-surface concentric to the opposed inner surface of the eye-loop for engagement with the concentric surface of the part to which the eyebolt is coupled, and a strap formed of a cylindrical rod looped into the eye of the part to which the eye-head is coupled, said cylindrical rod being bent to form the eye of the head and having its ends welded to the filler on opposite sides thereof, the-welded portions being shaped-into a peripherallythreaded conicfrustum, for the purpose described.

- 4. An articulated stay-bolt having an eyehead consisting of a central filler the inner edge of which is formed with concave bearingsurfaces with a depression between them, said concave bearingsurfaces being concen tric to the opposed inner surface of the eyeloop for engagement with the concentric surfaces of the part to which the eyebolt is coupled, and a strap formed of a cylindrical rod looped into the eye of the part to which the eye-head is coupled, said'cylindrical rod being bent to form the eye of the head and having its ends welded to the filler on oppo-- ILO site sides thereof, the welded portions being shaped into a peripherally-threaded conic frustum, for the purpose described.

5. An articulated stay-bolt having an eye head consisting of a central filler having recessed sides and an inner edge formed witha concave bearing-surface concentric to the opposed inner surface of the eye-loop for engagement with the concentric surface of the part to which the eyebolt is coupled, and a strap formed of a cylindrical rod looped into the eye of the part to which the eye-head is coupled, said cylindrical rod being bent to form the eye of the head and having its ends fitting'in the recessed sides of the filler and welded thereto, for the purpose described.

6. An articulated stay-bolt having an eyehead consisting of a central filler having re cessed sides and an inner edge formed with concave bearing-surfaces with a depression between them, said concave bearing-surfaces being concentric to the opposed inner surface of the eye-loop for engagement with the concentric surface of the part to which the eyebolt is coupled, and a strap formed of a cylindrical rod looped into the eye of the part to which the eye-head is coupled, said cylindrical rod being bent to form the eye of the head, and having its end fitting in the recessed sides of the filler and welded thereto, for the purpose described.

7. An articulated stay-bolt having an eye consisting of a central filler having recessed sides and an inner edge formed with a concave bearing-surface concentric to the opposed inner surface of the eye-loop for engagement with the concentric surface of the part to which the eyebolt is coupled, and a strap formed of a cylindrical rod looped into the eye of the part to which the eye-head is coupled, said cylindrical rod being bent to form the eye of the head and having its ends fitting in the recessed sides of the filler and welded thereto, the welded portions being shaped into a peripherally-threaded conic frustum for the purpose described.

8. An articulated stay-bolt having an eyehead consisting of a central filler having recessed sides and an inner edge formed with concave bearing-surfaces with a depression between them, said concave bearing-surfaces being concentric to the opposed inner surface of the eye-loop for engagement with the concentric surface of the part to which the eyebolt is coupled, and a strap formed of a cylindrical rod looped into the eye of the part to which the eye-head is coupled, said cylindrical rod being bent to form the eye of the head and having its ends fitting in the recessed sides of the filler and Welded thereto, the welded portions being shaped into a peripherallythreaded conic frustum for the purpose described.

9. An articulated stay-bolt having an eyehead formed with a body in the shape of a peripherally-threaded conic frustum with an eye-loop the inner surfaces of which are concentric, a link of less width than the threaded portion of the eye head, said link being formed with concentric surfaces for engagement with the concentric inner surfaces of the loop in the eye-head, and an eyebolt of less diameter than the eye-head and coupled to the latter by said link, for the purpose described.

10. An articultted stay-bolt having an eyehead formed with a body portion in the shape of a peripherally-threaded conic frustum with an eye-loop the inner surfaces of which are concentric, a link of less width than the threaded portion of the eye-head formed with concentric surfaces for engagement with the concentric inner surfaces of the loop in the eye-head, and also formed with concentric surfaces for engagement with the corresponding concentric inner surfaces of the loop of an eyebolt, and said eyebolt also of less diameter than the threaded portion of the eyehead, and formed with a loop having inner concentric surfaces for engagement with the link, for the purpose described.

11. An articulated stay-bolt having an eyehead formed with a body portion. in the shape of a p eripherally-threaded conic frustum with an eye-loop the inner surfaces of which are concentric, a link of less width than. the threaded portion of the eye-head formed with concentric surfaces for engagement with the concentric inner surfaces of the loop in the eye-head, and also formed with concentric surfaces for engagement with the corresponding concentric surfaces of the loop of an eyebolt, and said eyebolt also of less diameter than the threaded portion of the eyehead and formed with a loop having inner concentric surfaces for engagement with the link, said link being also formed. with a cen tral web between its eyes for the purpose described.

12. An articulated stay-bolt having an eyehead formed with a body portion in the shape of a peripherally-thread ed conic frustum with an eye-loop the inner surfaces of which are concentric, a link of less width than the threaded portion of the eyehead, formed with concentric surfaces for engagement with the concentric inner surfaces of the loop in the eye-head, and also formed with concentric surfaces for engagement with the correspondwith an eye-loop the inner surfaces ofwhich are concentric, a link of less width than the.

9'- ameter than the threaded portion of theeye= head and formed with a loop having inner concentric surfaces for engagement with the link, the eyes-in the said link being formed with semic rcular seats of the same diameter as the engaging portions of the loops of theeye-head and eyebolt respectively, and with spaces back of said semicircular seats of greater diameter than that of the seats for the pur ose described.

14. articulated stay-bolt having an eyehead formed with a body'portion in the shape of a peripherally-threaded conic frustum with an eye-loop the inner surfaces of which are concentric, a link of less width than the 2 5 threaded portion of the eye-head, formed with concentric surfaces for en agement with the concentric innersurfaces o the loop in the eye-head, and also formed with con centric surfaces for engagement with corre- 0 sponding concentric inner surfaces of the loop of an eyebolt, and said eyebolt, also of less diameter than the threaded portion of the eye-head and formed with a loop having inner concentric surfaces for engagement with the link, said link being formed in one piece without joint or weld, and the loops of the eyebolt and of the eye-head being formed of cylindrical rods which are passed through the eyes in the link and then bent 40 and welded to fillers, for the purpose 'described.

15. An articulated stay-bolt consisting of an eye-head the body of whi ch is in the form of a conical frustum threaded peripherally, a 5 screw-eyebolt, and a link coupling the screweyebolt to the eye-head, the joints between the parts being formed to allow of pivotal or lateral play only, so that the parts are sustained against longitudinal movement upon or with relation to each other, for the purpose described.

- 16. An articulated stay-bolt consisting of an eye-head the body of which is in the form of a conic frustum threaded peripherally, a threaded eyebolt, and a link coupling the said threaded eyebolt to the said eye-head, the eyebolt and the coupling-link being both of less width than the eye-head, and the joints between the parts being formed to allow of pivotal or lateral play only so as to sustain the parts against longitudinal movement upon or with relation to each other, for the purpose described.

17. An articulated stay-bolt formed with a threaded eyebolt having a nose of less diameter than the threaded portion of thebolt for thepurpose described. i

18; The combination. with boiler and fur nace. plates formed with opposed andcoinciding screw-holes, of. articulated stay:

bolt having an eye-head formed with. a bodyv portion in the shape of a peripherally-thread ed conic frustum, and a threaded eyebolt .coupledto the eye-headby a link having eyes which closely fit the loops of both the eye head and the eyebolt as to admit of pivotal or lateral flexui'e while preventing longitudinal movement between the parts, for the purpose described.

19 The combination withboiler and fur nace plates formed with opposed and coinciding screw-holes, of an articulated staybolt having an eye-head formed with a body portion in the shape of a peripherally-threaded conic frustum, and a threaded eyebolt coupled to the eye-head by a link having eyes which closely fit the loops of both the eye-head and theeyebolt, so as to admit of pivotal lateral fleXure while preventing longitudinal movement between the parts, said eyebolt being formed with' a nose of less diameter than its threaded portion for the purpose set forth.

20. The combination with boiler and furnace plates formed with opposed and coinciding screw-holes, of an articulated staybolt having an eye-head formed with a body portion in the shape of a conic frustum being formed with a telltale-bore opening into the fire-box, for the purposedescribed.

21. A three-part articulated stay-bolt consisting of two threaded eyepieces coupled together by a link formed of one solidpiece without joint or weld with a central web of greater thickness than the other parts of the link, for the purpose described.

22. A three-part articulated stay-bolt consisting of two threaded eyepieces coupled. together by a link, the link being formed with concentric bearing-surfaces at each end, and each eyepiece being formed with concentric bearing-surfaces which engage directly with those of the link so as to permit of pivotal flexure between the parts only, for the purpose described.

23. A three-part articulated stay-bolt consisting of two threaded eyepieces coupled together by a link, the link being formed with oblong eyes and with concentric bearing-surfaces at each end, and each eyepiece being formed with concentric surfaces which en- IIO gage directly with those of the link so as to permit of pivotal fiexure between the parts only, for the purpose described.

24. A three-part stay-bolt consisting of an eye-head and an eyebolt each formed with an internal convex semicircular seat in its eye and with an internal concave bearingsurface concentric to said convex seat, and a coupling-link interposed between the said eye-head and said eyebolt and formed with concentric bearingsurfaces which engage with said concentric surfaces on the eye-head and eyebolt, for the purpose described.

25. A three-part stay-bolt consisting of an eye-head and eyebolt each formed with an 

